Separation of valuable products from mixtures thereof with solid substances



Patented Sept. 5, 1933 SEPARATION- OF FROM MIXTURES HEREOF WITH SOLID SUBSTANCES Rudolf Wietzel, Ludwigshafen-on-the-Rhine, I

Germany,

and I Bruno Engel, Stockholm,

Sweden, assignors to-L; G. Farbenindustrie Aktiengesellschaft,

Frankfort-on-the-,Main,

Germany, a. corporation, of- Germany No Drawing.

Application May- 23, 1928. serial No. 280,114, and in Germany June 1,1927

12 Claims. (01. 196- 13) This invention relates to the recovery of valuable hydrocarbons and oils from mixtures thereof with solid substances, and to the production of the said hydrocarbons and oils from carbonaceous materials.

We have found that such hydrocarbons and oils may be recovered with particular advantage from mixtures thereof with solid substances, in particular from the crude solid or pasty products obtained by' low temperature carbonization, cracking and extraction of carbonaceous materials, and in the destructive hydrogenation of coals, tars, mineral oils and the like, which consist of mixtures of oils and other valuable hydrocarbons with solid substances such as carbonaceous residues, ash constituents, or other solid admixtures such as catalysts, by stirring the mixture, preferably at a slightly elevated temperature, with a liquid in which the oil is insoluble, or only slightly soluble, and to which an alkaline reaction has been imparted and which contains small amounts of a wetting or emulsifying agent, such as sulfonic acids of aromatic or aliphatic hydrocarbons, in particular nucleoalkylated sulfonic acids of aromatic hydrocarbons, cellulose pitch, saturated or unsaturated fatty acids, their salts and derivatives, glue, saponines, dextrine, oxidation products of paraffins, and the like. Products obtained by'sulfonating products of the destructive hydrogenation of coal, tars and the like are also suitable.

When the adhesion between the solid substances and the oils has been sufficiently loosened, the oil is separated .in various ways, as for example mechanically, as by centrifugal means, preferably in the warm, or by means of electric or magnetic fields, or in other suitable ways, or by the application of several methods of separation simultaneously.

The process may be applied alone or in combination with other methods, such as subsequent low temperature carbonization, or extraction and the like; and the mixtures may also be subjected to repeated treatment and to the action of different kinds of liquids. The conditions in respect of pressure and temperature may be varied within wide limits according to the character of the substances under treatment.

Materials suitable for treatment comprise, for example, the residues from the distillation of tar, cracking residues, crude mineral oils, the residues from the extraction of coal and the like, or the residues obtained in the heat treatment under pressure, with or without hydrogen, of

Y coals, peatycellulose, "tar,

oils, bitumen or other carbonaceous substances. I r

It has also been found suitable, in treating the oleaginous sludge,to employ solutions which also contain salts'such as chlorids, sulfates and the like/ If the concentration of these be such that the specific gravity of the solutions is equal to,

or greater than that of the solids to be separated,

it is easy to carry on the operations, for instance the centrifuging, continuously.

In centrifuging especially, there is no need to stir up the sludge under treatment with the added liquid beforehand in a special stage of the process, but the material under treatment and the added liquid may be introduced simultaneously into theseparator, such as a centrifuge. This not only saves one working stage, but also, in

certain circumstances, leads to a better separation of the oil and solid residue. The rate of separation of the material on the one hand, and the added liquid on the other, depends on the character of the former.

. The amount of emulsifying and wetting agents to be added is usually very small, for example 0.05 per cent or sometimes still less. The optimum quantity depends on the character of the material under treatment in each case. The other working conditions, such as temperature, speed of the centrifuge and the like, also depend on the mate rial under treament and on the wetting agent used, and must be determined by experiment in each case. For example, inrcentrifuging a coal sludge, such as is obtained, for example, in the extraction of coal with solvents under pressure, it is preferable to work at a temperature not exceeding 100to 110C. when an equal quantity of an 0.05:0.1 per cent aqueous solution, for example of alkylated naphthalenesulfonic acids, is added to the sludge during the centrifuging process.

The added liquid after being freed from oil by centrifuging may be used over again. i

The employment of the said substances adapted to reduce the surface tension, especially the emulsifying and wetting agents, for example the excellent yields of valuable, and especially liquid hydrocarbons are obtained.

These processes are hereinafter referred to for the sake of brevity as the production of valuable products by heat treatment of carbonaceous materials. The liquid employed in this case need not necessarily be rendered alkaline, although in some cases, this may be'advantageous.

This process is especially adapted for the extraction of any kind of coal, under pressure, with liquid organic solvents, comprising a great variety of substances (especially those of high boiling point range), and particularly fractions or transformation products of mineral oils or tars, such as cresols, xylene, naphthalene, anthracene oil, hydrogenation products of naphthalene or benzene, or mixtures of benzene and alcohol or halogenated hydrocarbons and the like.

The process may also be employed with advantage in the destructive hydrogenation, and also in cracking, since the said additions exerta split 'The operation may be conductedunder high pressures, such as 200 atmospheres, and when 'r ea' quired, with special addition of hydrogen oriother' gases, and also at pressures as low as about $50 .is passed into a large vessel in which separation atmospheres, in which event the excesspressure generated under certain conditions by the ,libera tion of gases from the coal, is released.

If the operation be carried on in' the presenc'e'of hydrogen, a portion of the coaly substance passing into solution is hydrogenated,"especially at tem-.

Example 1 If a 40 to 50 per cent solution of calcium chlorid,

to which is added 0.08 per cent'of sodium isopropylnaphthalene sulfonate be admitted into a separating drum at the rate of ,6 liters per sec- 0nd, and the sludge, (containing about per cent of solids) to be separated (obtained by extracting brown-coal with t ar'oilsunder. pressure) separator being run at 7000 revolutions per minute, a practically ash-free oilis obtainedas well as a residue still containing about 9 to 12per cent I of oil.

If the added liquid be slightly acidified' with a mineral acid, for example ihydrochloricacid, a

residue richer in oil and also-"an oil,- richer in i residue (about 4 to'6 per cent '}is obtained; On the other hand, if the added; liquid be rendered tained, together with-a resid only 4 to 6 per cent'iof oil, gor rstillfiles's-in "some cases. The added liquid remaining'adherent to the centrifuged solid residue; may be're'adily removed by pressing and theilike. The washing liquid is continuously recovere cir ulatiomr Example: I

A mixture of oil and carbonaceous. material obtained by the destructive hydrogenation of lignite is treated in a centrifuge with an equal amount of a weakly alkaline aqueous solution of 0.2 per cent strength of a product which is obtained by the oxidation of solid parafiin. Besides the oil, a residue is obtained containing per cent of products soluble in benzene. If the aforesaid product of the destructive hydrogenation is centrifuged with an addition of alkali alone, a residue is obtained containing 40 per cent of substances soluble in benzene. If the centrifuging of the mixture of oil and carbonaceous material is carried out without any addition at all, a residue containing per cent and even more of benzene soluble products is obtained. By means of suitable devices, for ejecting the material, for example by means of worm conveyors arranged within the centrifuge, the residue may be removed continuously.

Example 3 A mixture of oil and carbonaceous material as described in Example 2 is triturated in a vessel fitted with a stirrer having a high speed of rotation with 5 times the amount of an aqueous weakly alkaline solution of Turkey red oil of 0.2 per cent strength. The emulsion thus obtained gradually takes place. The carbonaceous sludge which is poor in oil collects at the bottom of the vessel and is then filtered off by suction. The upper layers which comprise an emulsion of oil in water are filtered off separately. In a further vessel the emulsion is destroyed by acidulating moderately and the oil which then colvlects on the surface of the aqueous solution may be collected and is pure.

By repeating thetreatment of the carbonaceous sludge which settles down at the bottom of the vessel, over per cent of the oil contained therein, can be recovered. The last traces of oil, can be removed by the aid of solvents. When operating without, an addition of alkali, only 40 'per cent or less of the oil can be obtained under otherwise similar conditions of working.

What we claim is':

. 1. A process for the recovery of hydrocarbon oils from a mixture thereof with solid substances obtained in a process of thermally converting carbonaceous materials, which comprises form ing a substantially stable emulsion of said oils in an added aqueous solution of a wetting and emulsifying agent in which solution said solid substances are insoluble and, to which solution an alkaline reaction has been imparted by an addition of alkali, and separating the solids from the liquids.

2. A processfor the recovery of hydrocarbon ,oils from a mixture thereof with solid substances obtained in a process of thermally converting carbonaceous materials, which comprises forming at a slightly elevated temperature a substantially stable emulsion of said oils in an added I aqueous solution of awetting and emulsifying merely faintlyalkaline, byftheaddition of'0,3 to- 1 per cent of caustic-soda,aniashfreetoilis 010-" which .contains' agentv in which solution said solid substances I are insoluble and, to which solution an alkaline reaction has been imparted by an addition of alkali, and separating the solids from the liquids.

3. A process for the recovery of hydrocarbon oils from a mixture thereof with solid substances obtained in a process of thermally converting.

carbonaceous materials, which comprises forming a substantially stable emulsion of said oils in an aqueous solution of a salt and of small amounts of a wetting and emulsifying agent in which solution said solid substances are insoluble and, to which solution an alkaline reaction has been imparted by an addition of alkali, and separating the solids from the liquids.

4. A process for the recovery of hydrocarbon oils from a mixture thereof with solid substances obtained in a process of thermally converting carbonaceous materials, which comprises emulsifying said oils in an added aqueous solution of a wetting and emulsifying agent in which solution said solid substances are insoluble and, to which solution an alkaline reaction has been imparted by an addition of alkali, and separating the solids from the liquids, the said process beingrendered continuous by freeing the added liquid from the bulk of the oils and hydrocarbons and returning it to the process.

5. A process for the recovery of hydrocarbon oils from a mixture thereof with solid substances obtained in a process of thermally converting carbonaceous materials, which comprises forming a substantially stable emulsion of said oils in an aqueous solution of a saponifiable product obtainable by the oxidation of parafiin wax in which solution said solid substances are insoluble and, to which solution an alkaline reaction has been imparted by an addition of alkali, and separating the solids from the liquids.

6. A process for the recovery of hydrocarbon oils from a mixture thereof with solid substances obtained in a process of thermally converting carbonaceous materials, which comprises forming a substantially stable emulsion of said oils 7 in an added aqueous solution of a wetting and emulsifying agent to which solution an alkaline reaction has been imparted by an addition of alkali, and separating the solids from the liquids by centrifuging.

T. A process for the recovery of hydrocarbon oils from a mixture thereof with solid substances obtained in a process of thermally converting carbonaceous materials, which comprises forming a substantially stable emulsion of said oils in an aqueous solution of a salt and of small amounts of a wetting and emulsifying agent, to which solution an alkaline reaction has been imparted by an addition of alkali, and separating the liquid from the mixture by centrifuging.

8. A process for the recovery of hydrocarbon oils from a mixture thereof with solid substances obtained in a process of thermally converting carbonaceous materials, which comprises forming a substantially stable emulsion of said oils in an aqueous solution of a saponifiable product obtainable by the oxidation of parafiin wax in which solution said solid substances are insoluble and, to which solution an alkaline reaction has been imparted by an addition of alkali, and separating the liquid from the mixture by centrifuging.

9. A process for the recovery of hydrocarbon oils from a mixture thereof with solid substances obtained in a process of thermally converting carbonaceous materials, which comprises introducing said mixture into a centrifuge simultaneously with an aqueous solution containing a small amount of a wetting and emulsifying agent in which solution said solid substances are insoluble and, to which solution an alkaline reaction has ben imparted by an addition of alkali, thus forming a'substantially stable emulsion of the hydrocarbon oils in the aqueous liquid and centrifuging the solid products ofi".

10. A process for the recovery of hydrocarbon oils from a mixture thereof with solid substances, said mixture being obtained in the destructive hydrogenation of carbonaceous materials, which comprises forming a substantially stable emulsion of said oils in an added aqueous solution of a wetting and emulsifying agent in which solution said solid substances are insoluble and, to which solution an alkaline reaction has been imparted by an addition of alkali, and separating the solids from the liquids.

11. A process for the recovery, of hydrocarbon oils from a mixture thereof with solid substances obtained in a process of thermally converting carbonaceous materials, which comprises forming a substantially stable emulsion of said oils in an added aqueous solution of a nucleoalkylated aromatic sulfonic acid in which solution said solid substances are insoluble and, to which solution an alkaline reaction has been imparted by an addition of alkali, and separating the solids from the liquids.

12. A process for the recovery of hydrocarbon oils from a mixture thereof with solid substances obtained in a process of thermally converting carbonaceous materials, which comprises emulsifying said oils in an added aqueous solution of sodium isopropyl naphthalene sulfonate in which solution said solid substances are insoluble and, to which solution an alkaline reaction has been imparted by an addition of alkali, and separating the solids from the liquids.

RUDOLF WIETZEL. BRUNO ENGEL. 

